Germicidal compositions



Patented Sept. 26, 1944 UNITED STATES PATENT OFFICE GERMICIDALCOMPOSITIONS Alexander M. Partansky, Midland, Mich., assignor to The DowChemical Company, Midland, Mich., a corporation of Michigan No Drawing.Application July 31, 1941,

Serial No.

11 Claims. (CL 167-31) The present invention is concerned with newgermicidal compositions, and is particularly directed to mixturescomprising water-soluble phenolates and alkaline reacting salts.

The water-soluble phenolates are well known as germicidal toxicants andhave found wide application in such use. These compounds are employed indispersions, solutions, emulsions, and powders adapted to be dilutedwith or dissolved in water or other solvents to produce germicidal,bactericidal, and antiseptic compositions.

The phenolates as a class have a tendency to break down on contact withwater to liberate free phenols which may be water-insoluble, less toxicto microorganisms, and more irritating to humans than the saltsthemselves. To prevent such hydrolysis and dissociation, it iscommonpractice to maintain an appreciable excess of alkali or alkalinereacting salt in compositions comprising the phenolates. Free alkali oralkaline detergent salts are frequently employed in combination withphenolates especially in germicidal cleansing powders, washingcompositions, and the like. Several disadvantages accrue to suchpractice. In the first place an excessively high alkalinity materiallylimits the application of a germicidal composition. More important isthe fact that in mixtures with many alkaline reacting materials, thegermicidal effectiveness and phenol coeflicient of the phenolate isreduced.

According to the present invention, germicidal compositions are providedwhich comprise as an active toxic ingredient a mixture of a,watersoluble phenolate with an alkali metal pyrophosphate. It has beenfound that water solutions of pyrophosphate-phenolate mixtures are ofrelatively lower pH yet resistant to hydrolysis and dissociation of thephenolate. The toxicity of the phate, sodium carbonate, or excess freealkali are employed, the pH of such aqueous solution may be somewhatraised by the addition of free alkali without materially ailecting thegermicidal activity of the solution.

The pyrophosphate and phenolate are compatible in any proportions andany suitable amounts of the two materials may be combined. Aqueoussolutions of the pyrophosphates alone have no appreciable germicidalpower at concentrations as high as 15 per cent by weight and the solidalkali pyrophosphates have phenol coefficients of less than 0.05. Inmixtures, however, of the pyrophosphates with phenolates in widelyvarying proportions, the apparent phenol coeflicient of the phenolate isappreciably in excess of that observed for the phenolate alone. Thepreferred percentage composition of the germicidal mixture with whichthe present invention is concerned varies somewhat with the particularphenolate and pyrophosphate employed. A percentage range of generalutility is that found specifically for sodium ortho-phenyl-phenolate andsodium pyrophosphate and consists of a mixture of 1 part by weight ofphenolate with from 0.33 to 49 parts of pyrophosphate, i. e., a mixturecontain.- ing from 2 to 75 per cent by weight of the phenolate.Preferred embodiments of the invention are compositions comprisingpotassium or sodium pyrophosphate. The latter has been found parphenolate in such pyrophosphate-phenolate mixture, measured in terms ofphenol coefiicient, is much higher than that accruing to phenolates inmixture with other alkaline reacting salts. A further embodiment of theinvention resides in the pyrophosphate-phenolate mixtures modified withcertain preferred groups of wetting and detergent agents.

In preparing the new compositions, the watersoluble phenolate andpyrophosphate are mixed together in any suitable fashion with or withoutthe inclusion of such wetting, dispersing, and detergent agents asfurther increase the efliciency of the phenolate in the mixture. Whilethe use of pyrophosphate results in a somewhat lower pH for diluteaqueous solutions of the compositionsthan is obtained when tri-sodiumphos- Health Service,

ticularly useful in the compositions as defined.

Sodium ortho-phenyl-phenolate constitutes a preferred phenolate for usetherewith,

The method for determining the phenol coeflicients as set forth in thefollowing examples is one developed by the United States Public HygenicLaboratory, and described in Circular 198 of the Food and DrugAdministration, United States Department of Agriculture. These valuesare based upon a coeilicient of 1.0 for pure phenol. The phenolcoeflicient of ortho-phenyl-phenol as the sodium salt according to thismethod is 16-171).

The following examples are not to be construed as limiting either withrespect to the proportions employed or the particular phenolatesdisclosed.

EXAMPLE 1 Finely ground sodium ortho-phenyl-phenolate was mixed withsodium pyrophosphate N arPzOv. 101-120) to obtain a series of dry whitepowders containing from 2.5 to 50 per cent by weight of the phenolate.These compositions were dissolved in water to obtain detergent andgermicidal solutions useful for the sterilization of drinking glasses,dishes, and silverware. Analogous series of mixtures were prepared inwhich tri-sodium phosphate, sodium carbonate and other alkaline reactingsalts were substituted for the sodium pyrophosphate initially employed.The following table sets forth the comparative efficiencies of thesodium ortho-phenyl-phenolat in the mixtures:

Table A Phenol coelfticient agains Composition of the test mixture E "mmat Sodium ortho-phenyl-phenolate:

Alone 17 With lpart N11100:" 9.5 With 3 parts NazCOa 5. 5 With 5 partsNazCOz. 7. 2 With 10 parts NazCOa..." 8. 3 With 1 part NB3P04-12Hz0 l6.7 With 3 parts Natl O4 12H2O.. 5. 5 With 5 parts N83P04.12H20 7. 1 With10 parts Na;PO4.12H2O 9. 6 With 1 part NB|P201JOII2O l8. 5 With 3 partsNa4PzO1.l0HzO 20. 2 With 5 parts N34P207.1OHQ0.... 20.

With 10 parts NmPzOyJOHzO Z3 With 25 parts Na4P O .l0HzO 20 With partsBorax and 1.2 grams NaOH In a similar manner portions of sodiumorthophenyl-phenolate were mixed with 2 and 5 parts by weight ofpotassium pyrophosphate In both of the compositions so obtained thephenolate was found to have a phenol coefficient of 22. In checkcompositions employing tri-potassium phosphate in mixture with thesodium-ortho-phenyl-phenolate, the compositions containing 2 and 5parts'of the phosphate per 1 part by weight of the phenolate the latterhad phenol coefiicients of 6.2 and 8.9, respectively.

EXAMPLE 2 1 part by weight of sodium carvacrolate was mixed with 5 partsof sodium pyrophosphate to obtain a composition in which the phenolatehad a phenol coefiicient of 31 against E. typhi at C. In compositionscontaining an equivalent amount of tri-sodium phosphate and sodiumcarbonate the carvacrolate had phenol coefficients of 13 and 18,respectively. The sodium carvacrolate alone has a phenol coeflicient of26 against E. typhz'.

Experiments were also made to determine the phenol coefficient of sodiumcarvacrolate against E. typhi when dissolved in 0.5 per cent solutionsof various alkali reacting salts. Such dilutions are the equivalent ofthose encountered in detergent sterilizing solutions as frequentlyemployed in eating places. In 0.5 per cent tri-sodium phosphatesolution, sodium carvacrc-late had a phenol coeflicient of 12. In 0.5per cent sodium carbonate solution, the phenol coefficient of thecarvacrolate was 18.5. In 0.5 per cent solution of sodium pyrophosphate,the phenol coefficient of the carvacrolate was 29.

EXAMPLE .3

In a similar manner sodium monochloro-carvacrolate was mixed with 10parts by weight of sodium pyrophosphate to obtain a composition in whichthe phenolate had a phenol coefiici t of against E. tuphi at 20 C. Thesodium monochloro-carvacrolate alone had a phenol coeflicient of 95. Incombination with 10 parts of sodium carbonate and of tri-sodiumphosphate, this compound had a phenol coefiicient of 27 and 22,respectively.

The phenol coeflicient of the sodium monochloro-carvacrolate in 0.5 percent aqueous sodium pyrophosphate solution was 120. In similar aqueouscompositions comprising 0.5 per cent sodium carbonate and tri-sodiumphosphate, the phenol coeflicients of sodium monochioro-carvacrolatewere found to be 30 and 27, respectively.

EXAMPLE 4 1 part by weight of sodium monochloro-orthophenyl-phenolatewas ground with 10 parts of sodium pyrophosphate to obtain a compositionin which the phenolate had a phenol coeflicient against E. typhi at 20C. of 92. Sodium monochloro-ortho-pheny1-phenolate alone had a phenolcoefiicient of 85. In combination with 10 parts by weight of sodiumcarbonate and of trisodium phosphate, the phenolate had phenolcoeflicients of 19 and 18, respectively.

In the presence of 0.5 per cent aqueous solution of sodiumpyrophosphate, the sodium monochloro-ortho-phenyl-phenolate had a phenolcoefficient of 75. In an analogous composition in which sodium carbonatewas substituted for the sodium pyrophosphate, the phenol coefllcient ofthe phenolate was but 13.0.

EXAMPLE 5 The phenol coeflicients of sodium para-chlorothymolate inmixture with several alkaline reacting salts were determined against E.typhi at 20 C. substantially as described above. In combination with 10parts by weight of sodium pyrophosphate, the sodiumpara-chloro-thymolate had a phenol coeflicient of 155. In combinationwith sodium carbonate and tri-sodium phosphate, the apparentcoeflicients of the phenolate were 63 and 30, respectively.

In 0.5 per cent aqueous solutions of sodium carbonate and tri-sodiumphosphate, sodium para-chloro-thymolate in each instance showed a phenolcoefficient of 33. In a 0.5 per cent aqueous solution of sodiumpyrophosphate, the apparent coefficient of the sodiumpara-chlorothymolate was over 150.

The pyrophosphate-phenolate mixtures as illustrated by the foregoingexamples may further be modified to impart even higher phenol coadditionof wetting and detergent agents generally to the pyrophosphate mixturedoes not cause an increase in the apparent pH of the phenolate, nor doesthe addition of the preferred agents to phenolate mixtures with commonalkaline reacting salts other than the pyrophosphates operate to thebenefit of the ultimate composition. It is believed that the chemicalconstitution of the ternary mixtures as hereinafter set forth iscritical.

EXAMPLE 6 Mixtures of sodium ortho-phenyl-phenolate with sodiumpyrophosphate were ground with a water-soluble salt of analkyl-aryl-sulfonate marketed as Santomerse #1. The following table setsforth the composition of the several mixtures and the phenol-coefllcientor the phenolate therein.

In a similar manner compositions were prepared by mixing sodiumortho-phenyl-phenolate and sodium pyrophosphate with a water-solublesalt of an alkyl-phenyl-phenol suli'onic acid sold as Aresklene 400 andbelieved to consist essentially of dibutyl-phenyl-phenol sodiumsulfonate. In a mixture of 1 part phenolate, 6 parts sodiumpyrophosphate, and 3 parts of Aresklene 400, the phenolate had a phenolcoefllcient of 25.

EXAMPLE 8 A similar beneficial result was obtained when the sodiumpyrophosphate mixture with sodium ortho-phenyl-phenolate was modifiedwith water-soluble salts of higher fatty alcohol sulfates andparticularly proprietory materials sold as Orvis, Brett, and GrasselliIN-lBl-P, all of which are believed to consist essentially of sodiumlauryl sulfate. The following table sets forth representative resultsobtained, and also illustrates the non-equivalence of compositions inwhich other alkaline reacting salts are substituted forsodium-pyrophosphate.

the examples. It is also sometimes advantageous to employ combinationsof 2 or more or the wetting and detergent agents as set forth above.

I claim:

1. A germicidal composition comprising as an active toxic ingredient amixture or from 2 to 75 per cent by weight 01' a water-soluble phenolatewith an alkali metal pyrophosphate, and substantially free of alkalinereacting salts which reduce the germicidal effectiveness of thewater-soluble phenolate.

2. A germicidal composition comprising as an active toxic ingredient amixture of a watersoluble phenolate with an alkali metal pyrophosphate,said mixture containing from 2 to 75 per cent by weight of the phenolateand being free from other inorganic alkaline detergent salts.

3. A germicidal composition comprising as an active toxic ingredient amixture of a watersoluble phenolate with a detergent salt selected fromthe group consisting of sodium and potassium pyrophosphates, saidmixture containing from 2 to 75 per cent by weight of the phenolate andbeing free from other inorganic alkaline detergent salts.

4. A germicidal composition comprising as an active toxic ingredient amixture of a watersoluble phenolate with sodium pyrophosphatef saidmixture containing from 2 to 75' per cent by weight of the phenolate andbeing free from other inorganic alkaline detergent salts.

5. A germicidal composition comprising as the active toxic ingredient amixture 01' a watersoluble phenolate with potassium pyrophosphate, saidmixture containing from 2 to 75 per cent by weight of the phenolate andbeing free from other inorganic alkaline detergent salts.

6. A germicidal composition comprising as the active toxic ingredient amixture of a watersoluble sodium phenolate with sodium pyrophosphate,said mixture containing from 2 to 75 per cent by weight of the phenolateand being free from other inorganic alkaline detergent salts.

Table C 555 95 Phenol coeffiortho- Parts of alkaline reacting salt Partsof wetting and dispersing agent ggggg gggf ggg fgg phenolate 1 6 isodiumhos hate 3 of Draft 30 l "2 i ffi aol'grvis l 6 of sodium pyrophospate.. o 1 di 11 hat l of Grasselli IN-181-P 32 1 f% fff?.."if. f mGrasselliIN-lSl-P.. 30 l 2 of sodium pyrophosphate o 31 l 4 of sodiumpyrophosphate 31 l 6 of sodium pyrophosphate.. 30 i 1 of sodiummetasilicate... 16 1 2 of sodium metasilicate. 13 l 411 o? sogiumcargonatteh. d 5 1 0 so iumcar ona e o 1 2 of sodiunii carbgnats]. .t go; grasseg} h1g1???" g 1 2oltri-sodurn 0s a e o rasse 1 .do f. B ,4 ofGrasselli IN-lSl-P 13. 8

Any of the other water-soluble salts of the phenols disclosed or thesodium, potassium, lithium, calcium, barium, ammonium, or magnesiumsalts of such other phenols as 4-hexy1 resorcinol,2-chloro-4-phenyl-phenol, 2.4.5-trichlorophenol, 2.4.6-trichlorophenol,2.4.5.6 tetrachlorophenol, pentachlorophenol,2-chloro-4-tertiaryamyl-phenol, 4-chloro-symmetrical-xylenol, ormixtures of 2 or more of such water-soluble phenolates may be employedin place'of those compounds shown in the examples. Similarly,mixedsodium and potassium Dyrophosphate may be substituted for thesubstantially pure compounds shown in organic wetting and detergentagent selected from the group consisting of water-soluble salts ofaikyl-aryl-sulfonates, higher fatty alcohol sulfates, andalkyl-phenyl-phenol sulfonic acids, and as an active toxic ingredient amixture of a water-soluble phenolate with an alkali metal pyrophcsphate,said mixture containing from 2 to '75 per cent by weight of thephenolate and being free from other inorganic alkaline detergent salts.

10. A germicidal composition comprising an organic wetting and detergentagent selected from the group consisting of the water-soluble salts ofalkyl-aryi-sulfonates, higher fatty alcohol sulfates, andaikyl-phenyl-phenol sulfonic acids, and as an active toxic ingredient amixture of sodium ortho-phenylphenolate with sodium pyrophosphate, saidmixture containing from 2 to 75 per cent by weight of the phenolate andbeing free from other inorganic alkaline detergent salts.

11. A germicidal composition comprising sodium lauryl sulfate and as anactive toxic ingredient a mixture of a water-soluble phenolate withsodium pyrophosphate, said mixture containing from 2 to 75 per cent byweight of the phenolate and being free from other inorganic alkalinedetergent salts.

ALEXANDER M. PARTANSKY.

